title: MRI-based surgical simulation of transtrochanteric rotational osteotomy for femoral head osteonecrosis.
abstract: Transtrochanteric rotational osteotomy (TRO) is one of the joint-preserving surgical treatments for osteonecrosis of the femoral head (ONFH). It can prevent collapse of the femoral head as necrotic lesions in the weight-bearing portion can be moved sufficiently to a less weight-bearing portion by anterior rotation, posterior rotation, or varus angulation. Patient selection and preoperative planning are important to determine indications for TRO. It has been reported that successful TRO requires at least 34% of the weight-bearing area supported by the intact part of the femoral head. However, this ratio is difficult to preoperatively quantify according to the rotation angle using conventional two-dimensional MR images or X-rays. Therefore, we developed a method of simulating TRO using three-dimensional (3D) models reconstructed from 3D MR images and applied it to serial patients with types C1 and C2 osteonecrosis at stage 1 or 2. The simulation visualized positional changes of the necrotic lesion in the weight-bearing area and enabled quantitation of the postoperative intact ratio. Our surgical simulation is useful for evaluating the postoperative intact ratio and for determining indications for TRO as well as the optimal angle of femoral head rotation and varus angulation.
authors.affiliation: Division of Robotic Therapy, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan. koyama_tsuyoshi@nifty.com
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Koyama
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Sugano
authors.forename: Takashi
authors.initials: T
authors.lastname: Nishii
authors.forename: Hidenobu
authors.initials: H
authors.lastname: Miki
authors.forename: Masaki
authors.initials: M
authors.lastname: Takao
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Sato
authors.forename: Hideki
authors.initials: H
authors.lastname: Yoshikawa
authors.forename: Shinichi
authors.initials: S
authors.lastname: Tamura
mesh_terms: D003198:Computer Simulation; D005270:Femur Head / Q000601:surgery; D005271:Femur Head Necrosis / Q000473:pathology / Q000601:surgery; D006801:Humans; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging; D010027:Osteotomy / Q000379:methods*; D018579:Patient Selection; D012399:Rotation; D016474:Weight-Bearing